Adiposity Distribution in Acute Respiratory Failure

Acute Hypoxemic Respiratory Failure (AHRF) is a condition in which injury to the lungs impairs the ability of the air sacs (alveoli) to ventilate and exchange oxygen. This impairment may be worsened in individuals with elevated body weight, particularly when fat tissue compresses the lungs and promotes alveolar collapse. The impact of body weight on lung function may be greater in individuals with upper-body fat distribution.

Two common interventions for AHRF-positive end-expiratory pressure (PEEP) and prone positioning-are used to improve lung ventilation. However, it is unclear whether these therapies are equally effective across different body weight categories and fat distributions.

This study will evaluate whether body weight and fat distribution affect patients' lung inflation responses to PEEP and prone positioning. Lung inflation will be assessed using electrical impedance tomography (EIT), a bedside imaging tool that maps lung ventilation, and esophageal manometry, which estimates lung compression through a thin catheter placed in the esophagus. Laboratory tests will also be used to measure markers of inflammation and AHRF severity and find correlations with fat distribution and responses to the tested treatments..

Patients with AHRF requiring mechanical ventilation will be enrolled across a range of body weights. Each participant will undergo combinations of two PEEP levels and two body positions (supine and prone) for 30 minutes each. At the end of the study procedures, clinical care will continue as determined by the treating team.